ACER one webcam not recognized by the kernel

Hello,

I bought a ACER netbook ref 0531H a couple of years ago. I installed the successive versions of Kubuntu without problems, especially with the integrated webcam (Suyin, Crystal Eye).
Skype, Cheese and Camorama worked fine with it. After upgrading to Kubuntu Precise (not sure), the webcam was not more correctly recognized by the kernel. Now the webcam looks to be recognized sometimes as a Sonix device, with error messages about "UVC compliance". Sometimes it isn't recognized at all.

I tried many things without success.

Detailed information :

Sometimes lsusb provides:

    Bus 001 Device 060: ID 0c45:6310 Microdia Sonix USB 2.0 Camera
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
    Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
    Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
    Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
    Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

Sometimes, the webcam didn't appear.

I tried with many kernels such as for Quantal or Raring (Dev):

    uname -rvpoi
    3.2.0-24-generic #37-Ubuntu SMP Wed Apr 25 08:43:52 UTC 2012 i686 i386 GNU/Linux

and

    uname -rvpoi
    3.7.0-3-generic #9-Ubuntu SMP Tue Nov 20 22:40:43 UTC 2012 i686 i686 GNU/Linux

In any case, the message in dmesg is similar :
dmesg | grep video

    [ 0.241729] pci 0000:00:02.0: Boot video device
    [ 15.772698] acer_wmi: Disabling ACPI video driver
    [ 508.803505] Linux video capture interface: v2.00
    [ 509.004525] uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:6310)
    [ 509.007843] uvcvideo: UVC non compliance - GET_DEF(PROBE) not supported. Enabling workaround.
    [ 509.008838] uvcvideo: Failed to query (129) UVC probe control : -32 (exp. 26).
    [ 509.008850] uvcvideo: Failed to initialize the device (-5).
    [ 509.010150] usbcore: registered new interface driver uvcvideo
    [11441.142956] uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:6310)
    [11441.144825] uvcvideo: UVC non compliance - GET_DEF(PROBE) not supported. Enabling workaround.
    [11441.145821] uvcvideo: Failed to query (129) UVC probe control : -32 (exp. 26).
    [11441.145833] uvcvideo: Failed to initialize the device (-5).

I tried to install the last version of the UVC driver but without any change: No correct recognization of the webcam (esp. no /dev/video0 device).

    http://git.linuxtv.org/media_build.git
    ./build
    sudo make install

    sudo camorama
    ==> device not found

I tried to create manually the /dev/video0 device by:

    xavier@mercure:/dev$ sudo mknod /dev/video0 c 81 0
    xavier@mercure:/dev$ sudo chmod 666 /dev/video0
    xavier@mercure:/dev$ sudo ln -s /dev/video0 /dev/video
    xavier@mercure:/dev$ sudo camorama
    ==> device not found